Hydraulic by-pass valve.



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f WILLS M. FLEMING, OF` IIOLYOKE, MASSACHUSETTS, ASSIGNOR, BY MESNE4 ASSIGN- MENTS, TO WORTHINGTON PUMP AND MACHINERY'CORPORA'TION, OF NEW YORK,

N. Y., A CORPORATION 0F VIRGINIA.

HYDRAULIC :BY-PASS VALVE.

To all ywhom t may concern Be it known that I, WILLs M. FLEMING, a citizen ofthe United States, residing at Holyoke, county of Hampden, and State of Massachusetts, have invented certain new and useful Improvements in Hydraulic By- Pass Valves, fully described and represented .in the following specification and the laccompanying drawings, forming a part of the same.

This invention relates to improvements in high pressure hydraulic by-pass valves whereby the discharge from power operated high pressure pumps delivering to an accumulator or directly to hydraulically operated machinery may be diverted during periods in which the discharge of the pump is not being utilized or otherwise when it is desired that the pump shall discharge against no load.

The-especial object of the invention is to produce a by-pass valve construction of this class that shall be simple and rugged in construction, with the pilot valve balanced soas to be suitable for very heavy pressures and h v which all fluttering of the by-pass valve or pilot valve shall be eliminated, and dancing of the accumulator piston avoided.

A further object of the invention is the production of a hydraulic by-pass construction in which the by-passing of the fluid shall be accomplished by a multiplicity of by-pass valves controlled and operated b v a single pilot valve and large flows and high pressures thus controlled with a pilot valve of moderate size.

For a full understanding of the invention a detailed description of a construction embodying the invention in itspreferred form will now be given in connection with the accompanying drawings forming a part of this specification and the features forming the invention will then be speciically pointed out in the claims:

In the drawings; Figure l is a central vertical section of a by-pass valve construction embodying the invention. Fig. 2 is a section on the line 2-2 of Fig. 1. Fig. 3 is a detail view of the device for securing a fullthrow of the pilot valve.

Referring to the drawings, a suitable casing 10, preferably formed of a single forged billet with Aall the water passages worked Specification of Letters Patent.

-Patented oct. 24, 1916.

Application led November 9, *1915. Serial No. 60,614.

out of the solid block, as shown, is provided Awith inlet 11 from the pump, connecting with inlet chamber 11 formed by a cross passage in the block, discharge 12 connecting with a passage forming discharge chamber 112', with spring pressed discharge valves 7 seated on discharge ports 8 between chambers 11', 12', of which valves and ports one is'shown, main by-pass port 13 and aux'- -1l1ary by-pass ports l-l, these by-pass ports 13, 14 connecting chamber 11 with waste or by-pass discharge casing 19 connected to the pump suction or other low pressure discharge, and being controlled by main and auxiliary by-pass valves 25, 26, the stems of which carry pistons 27 whichpistons work in pressure chambers 16, 17 -above the chamber 11k andconnected by passages 18. The passages and chambers are all bored in the block or casing 10. the ends of the bores at the sides otthe block being stopped by screw. plugs 9. Lever 20, operated by hand, or automatically by the position of the accumulator piston or otherwise, is fulcrumed in any suitable manner as at 21 on standard 22 and is connected to stem 23 of the pilot valve 21, seating and operating in main bypass valve 25. By-pass valve 25 is provided with a central passage 1, running the full length of the valve body and contracted at its lower end to provide a seat 2 for the end of the pilot valve 2l. A passage 3 in the piston 27 connecting with central passage 1 above the pilot valve establishes communication between the pressure chambers 16, 17, and the inlet chamber 11 and another passage l in the piston 27 connects the chambers 16, 17 with the lower portion of the passage 1. a short distance above seat 2. Pilot valve 21 is formed above seat 2 as a plunger valve vof such length as to control shoulder or jpiston 6 subject to the pressure s in chamber 16, the area of this shoulder or piston being such as to balance the downward pressure on the top of the. pilot valve when closed. The lever preferably ex- `tends beyond the pilot valve Vspindle .23 .and

works Vin a vgroove 28 in guide 29, andv is held in either its uppermost or lowermost position by the spring 30 'formed withqa bend 31,- acting upon a cam portion 32 provided at the end o'f'lever 20, so as to throw.

s the pilot 'valve to the end of itsmovement v operated machinery, and through passages 3g and 1, in the main by-pass valve piston 27 to the pressure chamber 16, and. through passages 18 to the auxiliary pressure chamber 17, thus/holding the by-pass valves 25, 26 closed bythe-pressure on the top of pis` tons 27. When the pressure fluid is togbe l by-passed, the lever 2O is operated by hand L or automatically., 'as arranged, to raise pilot valve 24 which, in l its upward movement, rstshuts rofl connection between passages f 3 and 1 so as to close the pressure chambers Y 16, 17 to the inlet and ropens the port through seat 2, and then opens passage 4 from pressure chamber 16 to discharge, thus reliev-y ing the pressure in chambers 16, 17. The main by-pass valve 25 and the auxiliary byresultfrom4 partial opening. Thepilot valve. is perfectlyl balancedwhen closed so that 1t may readily be operated by hand or a solenoid, notwithstanding veryv high pressures are used. Bloreover, withfan accumus lator and the demand upon the accumulator equal to the capacity of the pump delivering to 1t, the dancing of the accumulator piston, which results With'the usual by-pass valve constructions, on account of the repeated quick opening 'and closing of the by-pass valve, isprevented by my ,construction withV the lap on the pilot valve requiring an appreciable time for the pilot valve .to move from open to closed position, and vice versa. 80 rlhe use of a casing formed in a single forged .billet with the passages .worked therein, and metal to metal pressure joints, avoids the useof packing, stuffing boxes, gaskets, and such small parts, andl the use of very high pressures is thus made more practicable. The use of a plurality of by-pass valves lis much preferable for hydraulic systems of large flow at high pressure, a single large valve being more liableto wear and breakt will be understood that the invention, broadly considered, is not to be limited to the use of a pluralityof by-pass valves nor to a'casing formedl in a single block with 95 the passages worked therein, although these form specific features of my invention, but that a single by-pass valve and casings of other form may be used. It will be understood, also, that the invention is not to be limited to the exact formv or arrangement of by-pass and pilot valve arrangement illuspass valves 26 then open and the valves 7 trated, but that many modifications may be close and the pressure fluid will be by-passed through byfpass ports 13, 14 to the waste discharge 19. On the movement of lever 2O to close kpilot valve 24 to stop by-passing, the pilot valve first closes passage 4 s0 as to stop the flow of liquid from pressurechambers 16, 17, and then o-pens passage?,` to ad-l mit pressure fluid tothese chambers and closes the port through seat 2. There isno period, therefore, either in opening or closing the pilot valve during which pressure fluid is circulating through passages 3, 4, l' and over the pilot valve seat. v The avoidance of flow of pressure Huid from the inlet through the pilot valve port avoids the rapid cutting 'and quick destruc tion of the pilot valve and its seat', which would be causedby such high pressure flow,

and the fluttering of the pilot valve which would be thus caused and would result in pounding and breakage. The spring 30and s cam 32 assure the pilot valve,- and consey quently the by-pass valvesbeing full open or full shut, andI secure a quick throw ofthe pilot valve to'full open o`rI full shut position, and thus prevent the Wire drawing and s cutting ofthe valves and seats that would made withinrthe invention as defined by the claims.

Vhat I claim is:

1. In a hydraulic by-pass system, the combination with the by-pass valve and its pressure chamber for closing the valve, and inlet and outlet ports for said pressure chamber, of a Vpilot valve controlling said ports and arranged to close the inlet port before open ing theoutlet port on the opening movement 'of the pilot valve and to close the outlet port before opening the inlet port on the closing movement of theA pilot valve,

2. In a hydraulic by-pass system, the combination with the by-pass valve and its pressure chamber-*for closing the valve, and inlet and outlet ports for said pressure chamber, of a pilot valve having its end seated to close the outlet port and controlling said ports and carrying a plunger valve controlling the outlet'passage between the pilot valve seat and pressure chamber,` whereby the flow vof pressure fluid over the pilot valve seat is pre vented until the pilot valve is moved away from the seat and the outlet passage opened by the plunger portion of the valve.

3.v In a hydraulicby-pass system, the combination with the by-pass valve and its pressure chamber for closing the valve, and inlet and outlet ports for said pressure chamber,

of a pilot valve seated at its end to close the outlet port and carrying a plunger valve controlling the inlet port and the outlet passage between the pilot valve seat and pressure chamber, said pilot valve and ports being arranged to close the inlet port before opening the outlet port on the opening movement of the pilot valve and to close the outlet port before opening the inlet port on the closing movement of the pilot valve, whereby the pressure fluid does not iow over the pilot valve seat until the pilot valve has closed the inlet port and the further movement of the plunger valve has opened the outlet passage.

4. In a hydraulic by-pass system, the combination with the by-pass valve and its pressure chamber for closing the valve, of separate passages connecting with said chamber foadmitting and discharging pressure iuid from the chamber, and a single pilot valve valves.

controlling said passages.

5. In a hydraulic by-pass system, the combinatioh with the by-pass valve and its pressure chamber for closing the valve, of a balanced pilot valve controlling'the admission and discharge ,f pressure fluid. for said chamber.

6. In a hydraulic by-pass system, the combination with a plurality of by-pass valves and their pressure chambers for closing said valves, o f a single pilot valve controlling the admission and discharge of pressure fluid for the pressure chambers of all the by-pass 7. In a hydraulic by-pass bination with the by-pass valve and its pressure chamber for closing the valve, of a pilot valve controlling the admission and dis` charge of pressure uid for'said chamber, a member for moving said valve, and means brought into action' by the movement of said member for throwing the pilot valve into system, the com-I and holding it in full open or full shut position.

8. In a hydraulic by-pass valve construction, the block 10 having inlet and discharge Vchambers formed therein on different planes and connected by a passageadapted to receive a valve seat, and passages formed in the block at an angle to the inlet chamber and forming by-pass discharge ports and pressure chambers for the by-pass valves.

9. In a hydraulic by-pass valve construction, the block 10 having inlet chambers 11, 11 formed'therein at right angles to yeach other, discharge chamber 12 parallel with chamber 11 and connected therewith by lpassages adapted to receive valve seats, and

passages formed in the block at right angles to the inlet chamber 11 and forming by-pass discharge ports 13, 14, and pressure chambers 16, 17 for the by-pass valves.

10. The combination with by-pass valve 25 and its stem and piston 27 thereon, having inlet passages 3, 1, connecting the pressure chamber with the inlet chamber andA outlet passage 4 connecting with the by-pass discharge, and seat 2 for the end of the pilot valve, of pilot valve 24 seated at its end to close the discharge and having a plunger valve ortion controlling passages 3, 4.

11.4 n -a hydraulic by-pass system, the' combination with the by-pass valve and its pressure chamber for closing the valve, of a pilot valve controlling the admission and discharge of pressure fluid for said cham` ber, lever 20 for moving the pilot valve havling cam 32, Aand spring 30 having cam portion 31 co-acting with cam 32 to throw the pilot valve into and hold it in full open or full shut position. l

' yIn testimony whereof, I have hereunto set my hand, in the presence of two'subscribing witnesses.

. WILLS M. FLEMING.

Witnesses:

THos. H. WESTPHAL, MAURICE A. FEENEY. 

